I am currently working on an iOS app that connects to Parse and I am having difficulty in retrieving objects using the includeKey() function.
Lets say that I am adding a food item to my Food table:
var newFoodObject = PFObject(className: "Food")
//Here I am pointing to an existing object in my SubCategory table
newFoodObject["subCategory"] = PFObject(withoutDataWithClassName: "SubCategory", objectId: "oisii1pZSP")
newFoodObject.saveInBackgroundWithBlock { (success: Bool!, error:NSError!) -> Void in
println(success)
println(error)
}
Then lets say I want to retrieve that object:
var query = PFQuery(className: "Food")
query.includeKey("subCategory")
query.findObjectsInBackgroundWithBlock { (objects:[AnyObject]!, error:NSError!) -> Void in
println(objects)
println(error)
}
For some reason when I do this the SubCategory object is not included in the query coming back unless I save the SubCategory in an array in my Food table.
Any thoughts why the includeKey() functions works with an array of pointers but not with a single pointer?
Related
I have a PFObject, Account that contains an array of Users which are subclasses of PFUserss. The User then has a NSDictonary property, allowableApps, that's a NSDictionary of arrays, where they arrays contain PFObjects.
So as a structure:
Account
var users: [User]
which points to....
User
// Each key is an array of AllowApp
var allowableApps: NSMutableDictionary
which points to...
AllowableApp
var appName: String
var appURL: String
var isAllowed: Bool
I'm trying to fetch all of these relations down to AllowableApp in a single query. I've tried using the .includeKey like this:
accountQuery?.includeKey("users")
accountQuery?.includeKey("allowableApps")
which didn't work. I've also tried:
accountQuery?.includeKey("users.allowableApps.appName")
accountQuery?.includeKey("users.allowableApps.appURL")
accountQuery?.includeKey("users.allowableApps.isAllowed")
I try to populate a UITableView with all the AllowableApp objects but I get this error:
Key "appName" has no data. Call fetchIfNeeded before getting its value.
Which I understand, I need to fetch all of them before trying to access the appName property. (which I'm trying to set cellForRowAtIndexPath).
Here is my full query:
let currentUser = User.currentUser()
let accountQuery = Account.query()
accountQuery?.whereKey("primaryUser", equalTo: currentUser!)
accountQuery?.includeKey("users.allowableApps")
accountQuery?.getFirstObjectInBackgroundWithBlock({ (account, error) in
if (error != nil) {
completion(users: nil, error: error)
}
else {
let users = (account as? Account)!.users
completion(users: users, error: nil)
}
})
My thought right now is to just loop through all of the AllowableApp objects in viewDidAppear calling fetchInBackgroundWithBlock. Then once they are all loaded I reload the table data.
This seems realllly messy and a common problem. Is there a more elegant solution that I'm just not seeing?
From what i understand you have the following structure:
Account
Users (Array of User)
AllowsableApps (Array of AllowApps)
First of all change the NSMutableDictionary to Array. NSMutableDictionary is a key-value pairs and in parse you should create one field. So you can use Array of AllowApps and it will do the same effect.
In order to fetch all accounts and users in each of the account and allowable apps per user you need to build the following query:
// You can do it with sub classing if you want
let query = PFQuery(className: "Account")
query.includeKey("users.allowableApps")
query.findObjectsInBackgroundWithBlock {
(objects: [PFObject]?, error: NSError?) -> Void in
}
Now for your users array. If your users array is users that needs to login the app it's better to inherit from PFUser and not from PFObject because PFUser contains all the logic for handling users in your app.
My query aims to fetch the objects created by a certain number of users. The following are my codes:
var dates = [NSDate]()
var messages = [String]()
let getUsersQuery = PFQuery(className: "followings")
getUsersQuery.whereKey("follower", equalTo: PFUser.currentUser()!.objectId!)
getFollowedUsersQuery.findObjectsInBackgroundWithBlock { (objects, error) -> Void in
if let objects = objects {
for object in objects {
let followedUser = object["followedUser"] as! String
let getPostsQuery = PFQuery(className: "posts")
getPostsQuery.whereKey("userId", equalTo: followedUser)
getPostsQuery.orderByDescending("updatedAt")
getPostsQuery.findObjectsInBackgroundWithBlock({ (objects, error) -> Void in
if let objects = objects {
for post in objects {
self.dates.append(post.createdAt as NSDate!)
self.messages.append(post["message"] as! String)
}
print(self.dates)
self.myTableView.reloadData()
})
}
}
}
})
Here's what come up when I print the dates in the log:
However, the content in my tableview is not in an ascending order. In fact the post created most recently is at the bottom of the tableview. One thing I noticed is that the posts of a particular user seems to be shown together. So all of one user's post would appear at the top of the tableview no matter another user has created the newest post. Any idea what is going wrong? thanks!
What you need is a nested query. The array you are trying to get is an of posts. So your query should be on the post table. (Also, your table should be called post not posts. Table names should always be singular. Each post is called a post not a posts.
let postsQuery = PFQuery(className: "post")
postsQuery.orderByDescending("updatedAt")
let usersQuery = PFQuery(className: "following")
usersQuery.whereKey("follower", equalTo:PFUser.currentUser()!.objectId!)
// this might need to change depending on what the followed user is called in the `followings` table.
postsQuery.whereKey("userId", matchesKey:"followed", inQuery:usersQuery)
getPostsQuery.findObjectsInBackgroundWithBlock({ (objects, error) -> Void in
if let objects = objects {
for post in objects {
self.dates.append(post.createdAt as NSDate!)
self.messages.append(post["message"] as! String)
}
print(self.dates)
self.myTableView.reloadData()
})
Also, you are saving dates and messages in separate arrays. Create a struct or something that has a date and string and have a single array of Post objects.
I am working on an app where the user is connected (in) multiple school classes. Since a student will be in more than one class, am I able to set an array of pointers to an individual user or is that not possible (maybe a relation is better)?
Here is my code:
let classPointerQuery = PFQuery(className: "Classes")
classPointerQuery.whereKey("class_name", equalTo: self.classNameTextField.text!)
let classQuery = PFQuery.orQueryWithSubqueries([classPointerQuery])
classQuery.findObjectsInBackgroundWithBlock({ (results: [PFObject]?, error: NSError?) -> Void in
if let objects = results {
for object in objects {
let userInfo = PFUser.currentUser()!
userInfo["my_classes"] = object
userInfo.saveInBackgroundWithBlock({ (success: Bool, error: NSError?) -> Void in
if error != nil {
spinningActivity.hideAnimated(true)
self.displayAlert("Error", message: error!.localizedDescription)
} else if success {
spinningActivity.hideAnimated(true)
self.dismissViewControllerAnimated(true, completion: nil)
} else {
spinningActivity.hideAnimated(true)
self.displayAlert("Something Went Wrong", message: "Please try again")
}
})
}
}
})
* Note: I also tried changing - userInfo["my_classes"] = object - to - userInfo["my_classes"] = [object] - and got an error, "invalid type for key my_classes, expected *Classes, but got array (Code: 111, Version: 1.12.0)"
What I am doing here is querying for the object of the class that I want - lets say the user wants to add the class "Physics" - the query queries for the "class_name" in the Parse class "Classes" and spits out the object. This object is then set the current user's "my_classes" -> a pointer object. I there a way, when the user wants to add "Calculus" that the pointer object in Parse will have 2 pointers instead of replacing the current pointer?
Thanks in advance for the help!
you cant store Pointers in array, you can store objectID in the array as string and do the query like that.... the general rule is that u use Pointers for 1:many relationships in database and Relations in many:many...
Update 1 - Saving objectID to Array in Parse
PFUser.currentUser()!.addObject(somePFObject.objectID!, forKey: "my_classes")
for queries you will than use containedIn
querySetup.whereKey("class", containedIn: array)
I am trying to do a multiple PFQuery and storing the data properly.
My plan is to query for group members in my Group
I am looking for the key member. It gives me an array of objectIds. Then I want to query in my _User class for their picture with key firstImage. Displaying the data is not the problem, just getting it the right way.
The data needs to be stored considering it's groups. This is what i tried so far:
let fetchGroupsQuery = PFQuery(className: "Group")
fetchGroupsQuery.whereKey("member", equalTo: objectID!)
fetchGroupsQuery.findObjectsInBackgroundWithBlock { (objects, error) -> Void in
if error != nil
{
}
else {
if let objects = objects {
self.memberPhotos.removeAll()
for object in objects {
if let member = object["member"] as? [String]
{
// returns array of objectIds
for user in member
{
// returns single ids
self.groupIds.append(user)
let photoQuery = PFUser.query()
photoQuery?.whereKey("objectId", equalTo: user)
photoQuery?.findObjectsInBackgroundWithBlock({ (results, error) -> Void in
if error != nil {
// ....
}
else {
self.memberPhotos.removeAll()
if let results = results
{
for result in results
{
if result["firstImage"] != nil
{
self.memberPhotos.append(result["firstImage"])
}
}
}
}})
}
}
My idea was to store the data within an array of arrays.
So that I can later go into array[indexPath.row] to get the array I need to loop through in order to get the right group pictures.
Any ideas how to solve this?
I would use two separate queries function:
1) to get their ID's
2) for their pictures.
For the first query: what you need to change?
Your objectID array should be of type of NSMutableArray because in order to fetch their info you should use the constraint whereKey containedIn not whereKey equalTo
and for that constraint you should downcast your NSMutableArray to type AnyObject.
Also change the Type of your groupIds to NSMutableArray, then append your array.
For the Second query:
Since your groupIds Type is already NSMutableArray just cast it to AnyObject,then use the whereKey containedIn
Note: It would be better to download all images before appending your
array. So you have the option of using struct or class(easier to
group data to its owner) then create an array of that data
structure.Where it because easier to populate your UI.
I have an app that I need to grab all values in the class. I need to get "players" and "total" from the class "runningTotal". Here is the code I have:
var query = PFQuery(className:"runningTotal")
query.selectKeys(["players", "total"])
query.findObjectsInBackgroundWithBlock
{
(objects: [AnyObject]!, error: NSError!) -> Void in
if error == nil
{
self.test = objects[0]["total"]
}
}
I want to set a variable (test) equal to the result of total. I would also want to do this with players. I don't think the above code is right, as it doesn't work. I obviously don't need any constraints as I want to fetch all of the results from this class. How would I go about solving this?
Thanks for any help in advance!
As long as your query is error free, you'll need to iterate through the objects array. As you iterate through each object, which will be of type AnyObject, you will need to cast the object as a PFObject. Then you will be able to grab the data you require from it.
var query = PFQuery(className:"runningTotal")
query.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]!, error: NSError!) -> Void in
if error == nil{
for object in objects{
if let data = object as! PFObject{
//Set test to total (assuming self.test is Int)
self.test = data["total"] as! Int
}
}
}else{
//Handle error
}
}